[UPDATE] Microsoft has confirmed that the leaked theme music and Warzone images are indeed legitimate. In a statement, Microsoft called the leak "unfortunate."

"It's unfortunate when work-in-progress content leaks, but this Halo 5: Guardians content is part of our ongoing private, external testing for multiplayer. We will continue to rigorously test Halo 5: Guardians to ensure the best possible experience for fans at launch."

First, the theme music. According to the Halo Memes YouTube account, the Halo 5 beta from December 2014 received an update this week that includes the audio you hear below for the main menu. The beta is still not playable, but you can listen to the lovely music through the video embed below.